recover learn codes from old source

ref.
https://github.com/Portisch/RF-Bridge-EFM8BB1/wiki/0xA2 (desc: Learning OK)
https://github.com/Portisch/RF-Bridge-EFM8BB1/wiki/0xA3 (desc: Learning failed)
were used, but the pages did not reflect the actual implementation:

af1bddb3d8/inc/uart.h
...
RF_CODE_LEARN_KO = 0xA2
RF_CODE_LEARN_OK = 0xA3
...

code/espurna/rfbridge.cpp

@@ -102,8 +102,8 @@ constexpr uint8_t CodeAck { 0xA0u };
 constexpr uint8_t CodeLearn { 0xA1u };
 
 // receiving:
-constexpr uint8_t CodeLearnOk { 0xA2u };
-constexpr uint8_t CodeLearnTimeout { 0xA3u };
+constexpr uint8_t CodeLearnTimeout { 0xA2u };
+constexpr uint8_t CodeLearnOk { 0xA3u };
 constexpr uint8_t CodeRecvBasic = { 0xA4u };
 constexpr uint8_t CodeSendBasic = { 0xA5u };